Pink Floyd managed to get to No.1 and sell a few million copies of Atom Heart Mother, one of the world’s most progressive psychedelic albums, without either a title or a band photo on the front– just a cow. Storm Thorgerson took the picture using only two rolls of 120 film in the first field he came to driving north out of London. No graphics, no retouching. ‘I wanted to design a non-cover, something that was not like other covers, particularly not like other rock or psychedelic covers – something that one would simply not expect. Not shocking, not mind altering, just unexpected. The cow was, in fact, more eye-catching than I had ever dared imagine; it was so different because it was so normal: so ordinary it stood out a mile. The cow was your regular cow, your standard cow, what every cow should look like’. To Pink Floyd the cow seemed suitably resonant, but unrelated and certainly open to different interpretations. For them, Atom Heart Mother was the big breakthrough in the UK despite the fact that the record company hated the cover. Still, nobody knows the nature of the link between sales and design, if one exists at all....